solve the system by the substitution method x+y=0 8x-8y=0

To solve the system of equations using the substitution method, solve one equation for one variable and substitute it into the other equation.

Given:
1) x + y = 0
2) 8x - 8y = 0

We can solve equation 1 for x in terms of y:
x = -y

Substitute this into equation 2:
8(-y) - 8y = 0
-8y - 8y = 0
-16y = 0
y = 0

Now substitute the value of y back into equation 1 to solve for x:
x + 0 = 0
x = 0

Therefore, the solution to the system of equations is x = 0 and y = 0.